Fixation device for a subcutaneous electrode

ABSTRACT

An illustrative anchoring mechanism is provided for attachment to an implantable subcutaneous lead to facilitate anchoring at the distal tip of the lead. The anchoring mechanism is attached to an opening in a distal portion of a subcutaneous lead prior to implantation. The anchoring mechanism may be designed to avoid covering the sensing electrode of the subcutaneous lead, to prevent interference with sensing. Use of such an apparatus may reduce the number of incisions needed to perform implantation.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/285,519, filed on Oct. 5, 2016, titled FIXATION DEVICE FOR ASUBCUTANEOUS ELECTRODE, which claims the benefit of and priority to U.S.Provisional Patent Application Ser. No. 62/237,755, filed Oct. 6, 2015,titled FIXATION DEVICE FOR A SUBCUTANEOUS ELECTRODE, the disclosures ofwhich are incorporated herein by reference.

BACKGROUND

The S-ICD System™ from Cameron Health, Inc., and Boston ScientificCorporation presents a new opportunity in cardiac rhythm management toreduce the complications associated with transvenous defibrillatorsystems. The defibrillator system itself may be implanted subcutaneouslywithout accessing the vasculature or touching the heart.

An illustration is provided in FIG. 1. The system is implanted in apatient 10 with a canister 12 in the left axilla at about the level ofthe cardiac apex. A lead 14 is placed subcutaneously, beneath the skinand over the ribcage of the patient, with a first portion extendingalong the inframammary crease to the xiphoid, and then superiorlyparallel to and about 1-2 cm to the left of the sternum. A proximalsense electrode 16, shocking coil electrode 18, and distal tip senseelectrode 20 are provided along the parasternal portion of the lead 14.The entire system is implanted outside of the ribcage.

The canister 12 may further include such components as would beappropriate for communication (such as RF communication, inductivetelemetry or other suitable communication linkage) with an externaldevice such as a programmer 22. For example, during an implantationprocedure, once the canister 12 and lead 14 are placed, the programmer22 may be used to activate the canister 12 and/or direct/observediagnostic or operational tests. After implantation, the programmer 22may be used to non-invasively determine the status and history of theimplanted device. The programmer 22 in combination with the canister 12may also allow annunciation of statistics, errors, history and potentialproblems to the user/medical practitioner, and may also allow forupdating of programming in the canister 12.

As shown in FIG. 2, a typical implant for the S-ICD System uses threeincisions 30, 32, 34, and a sterile field represented by shape 36 isused to avoid the introduction of microorganisms that can causeinfection. Some physicians have also used a two-incision approach byforegoing the superior sternal incision 34.

The subcutaneous-only placement prevents some of the more dangerouscomplications associated with infection, in particular, endocarditiswhich can result when an infection travels down a transvenous lead intothe heart. However, infections, both systemic and superficial have beenreported. In addition, some reports have shown that air pockets ateither of incisions 32 or 34 can lead to inappropriate shocks within thefirst few weeks of implantation.

Alternatives and additional options are desired to reduce the number ofincisions.

OVERVIEW

The present inventors have recognized, among other things, that aproblem to be solved is the anchoring of a subcutaneous lead. Ananchoring device is provided for attachment to the implantablesubcutaneous lead to facilitate anchoring at the distal tip of the lead.In some examples, the anchoring mechanism is attached at an opening inthe distal end of a subcutaneous lead prior to implantation. Theanchoring mechanism may be designed to avoid covering the sensingelectrode of the subcutaneous lead, to prevent interference withsensing.

In a first illustrative embodiment, an anchoring device for use with asubcutaneous lead may comprise one or more arms, a body coupling the oneor more arms together and having a nose on one end thereof, and anattachment feature for attaching to a distal tip of the subcutaneouslead.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, the attachment feature may comprise apost extending in a lateral direction relative to a direction from theattachment feature to the nose, such that the post is configured toplace through an opening in the tip of the subcutaneous lead.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, a securing piece for securing to thepost, wherein the securing piece and the post snap fit together.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, the securing piece, attachment featureand body may be configured to mate together with the distal tip of thesubcutaneous lead to form a smooth transition therebetween.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, the post may include an expanded portionat a tip therefor, the expanded portion configured to pass through anopening, such as a suture hole of the subcutaneous lead in asnap-through fashion and remain secured to the subcutaneous lead afterpassing through the opening.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, the attachment feature may comprise ahook for passing into an opening, such as a suture hole in the tip ofthe subcutaneous lead.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, the attachment feature may furtherinclude a latch to allow entry of the subcutaneous lead an opening, suchas suture hole, to the hook, but preventing escape therefrom.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, the body may comprise a bore having aclosed end near the nose and an open end for receiving a portion of thedistal tip of the subcutaneous lead, and the attachment feature is asuture secured to the body within the bore.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, the suture may be long enough to allowthe lead to be outside the bore while remaining attached to the suture.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, the attachment feature may be a tabhaving an opening, such as a suture hole therethrough to allow a sutureor surgical staple to be used to secure the tab to the opening of thesubcutaneous lead.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, the arms, body and attachment feature maybe formed of a single piece.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, a dissolvable portion that may act as afiller during introduction of the anchoring device and an associatedsubcutaneous lead into a patient, and then, once dissolved by tissuefluids after implantation, to create a space between the body and theanchored subcutaneous lead.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, the arms may be flexible and configuredto collapse for introduction through an introducer sheath.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, the arms may include a radiopaque coatingthereon.

Additionally, or alternatively, in some embodiments according to thefirst illustrative embodiment, the device may further comprise one ormore radiopaque strands or filaments therein.

In a second illustrative embodiment, a method of implanting asubcutaneous lead having a plurality of electrodes thereon and a distaltip having an opening, such as a suture hole may comprise securing ananchoring device to the distal tip using the opening prior to implantingthe lead and advancing the lead, with the anchoring device securedthereto, through a subcutaneous tunnel to a desired implant location.

Additionally, or alternatively, in some embodiments according to thesecond illustrative embodiment, the method may further comprise using anintroducer tool having a sheath thereon for creating the subcutaneoustunnel and removing the introducer tool to leave the sheath in place,wherein the step of advancing the lead, with the anchoring devicesecured thereto, is performed by advancing the lead and anchoring devicethrough the sheath.

Additionally, or alternatively, in some embodiments according to thesecond illustrative embodiment, the anchoring device may comprise one ormore arms thereon for anchoring in subcutaneous tissue, the one or morearms are flexible, the step of advancing the lead and anchoring devicethrough the sheath is performed with the arms in a collapsedconfiguration, and upon completion of the step of advancing the lead andanchoring device through the sheath, the sheath is removed, allowing thearms to return from the collapsed configuration to an extendedconfiguration for anchoring within the subcutaneous tissue.

Additionally, or alternatively, in some embodiments according to thesecond illustrative embodiment, the anchoring device may comprise one ormore arms, a body coupling the one or more arms together and having anose on one end thereof, and an attachment feature for attaching to adistal tip of the subcutaneous lead.

In a third illustrative embodiment an anchoring device for use with asubcutaneous lead may comprise one or more flexible arms, a bodycoupling the one or more arms together and having a nose on one endthereof, and an attachment feature for attaching to a distal tip of thesubcutaneous lead, wherein the attachment feature is a snap-fit, asuture, or a hook.

This overview is intended to provide an overview of subject matter ofthe present patent application. It is not intended to provide anexclusive or exhaustive explanation of the invention. The detaileddescription is included to provide further information about the presentpatent application.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various embodiments discussed in the presentdocument.

FIG. 1 shows an illustrative subcutaneous-only implantable cardiacstimulus system in an implanted state;

FIG. 2 illustrates certain aspects of the procedure to implant a deviceas in FIG. 1;

FIG. 3 shows an implantable lead similar to that of FIG. 1;

FIGS. 4A-4B are detail views of the distal tip of the lead of FIG. 3;

FIG. 5 is an exploded view of a first anchoring device;

FIG. 6 is an assembled view of the first anchoring device of FIG. 5;

FIG. 7 shows the first anchoring device secured on the distal tip of alead;

FIG. 8 shows a second anchoring device relative to the distal tip of alead using a suture for attachment to the lead;

FIGS. 9A-9B show a third anchoring device;

FIG. 10 shows insertion of a lead with an anchoring device thereonthrough a sheath;

FIGS. 11A-11B show a fourth anchoring device;

FIG. 12 shows a fifth anchoring device;

FIG. 13 shows a lead insertion tool having a sheath thereon;

FIG. 14 is a block diagram for an illustrative method.

DETAILED DESCRIPTION

As explained above, FIG. 1 shows an illustrative subcutaneous-onlyimplantable cardiac stimulus system in an implanted state. FIG. 2illustrates certain aspects of the procedure to implant a device as inFIG. 1. In this illustration, the procedure for implantation calls forthe use of three incisions at locations 30, 32 and 34. To reduce therisk of infection, a sterile field including approximately area 36 maybe prepared. This largely tracks the method of implant described in thelabeling approved in the United States for the S-ICD® System fromCameron Health and Boston Scientific at the time of approval by the FDAin 2012.

However, in many patients, this sterile field 36 will include variousskin folds, for example with obese patients and/or due to proximity tothe left breast. It is not always easy to get this area 36 clean forsurgery, let alone keeping it clean and dry during the days or weeksafter surgery while the incisions 30, 32, 34 all heal. For somepatients, the incisions along the sternum may also present aestheticconcerns, for example, because incision 34 may leave a scar that can bevisible when wearing ordinary and common clothing and incision 32 may beclearly visible when wearing swimwear.

Reducing the number of incisions has been proposed. Some may use, forexample, a two-incision technique similar to that described in someembodiments of U.S. Pat. No. 7,655,014, the disclosure of which isincorporated herein by reference. In this technique, after tunnelingbetween incision 32 and incision 30 and pulling the lead therethrough,an introducer tool having a splittable sheath is advanced from incision32 toward the manubrium along the sternum, without making incision 34 atall. Next, the introducer tool is removed, leaving the sheath behind,and the lead is introduced through the sheath. Finally the sheath issplit and removed over the lead. This approach relies on a suture sleeveat the xiphoid incision to secure the lead in place and preventmigration thereof. It may be desirable to provide additional anchoringfor the lead near its distal tip along the upper sternum.

FIG. 3 shows an implantable lead similar to that of FIG. 1. The lead 50has a proximal end with a proximal pin 52 which serves in this exampleas an electrical contact, along with additional contacts 54, 56, whichare separated by insulating material 58. Seal plugs are shown at 60. Aproximal plug sheath 62 is provided for a region near the proximal endof the lead 50. The pin 52, contacts 54, 56, insulating material 58 andseal plugs 60 are configured for placement inside a bore on a header ofan implantable pulse generator. The lead 50 extends from this proximalconfiguration through an intermediate region 64 to a distal end having aproximal electrode 66, a coil electrode 68, and a distal tip electrode70. Some illustrative discussion of a lead as used in the S-ICD™ Systemis provided in U.S. Pat. No. 8,483,841.

Lead 50 is shown for illustrative purposes, however, other designs andconfigurations including fewer, more or different electrodes 66, 68, 70,or contacts 52, 54, 56, may be used. Additional design elements such asbifurcation or other splitting, paddles or other designs may be usedinstead with an anchoring device attached at the time of implant. Thelead 50 is not shown as including a passageway for a stylet to useduring introduction, however, a lumen for that purpose may be providedif desired.

In the illustrative example, the lead 50 has a body that containspassageways having connectors therein for coupling the proximal contacts54, 56 to the coil 68 and proximal electrode 66. The proximal pin 52 inan example is connected to the distal tip 70 by a stainless steel wireon which the lead body is coextruded lending significant pull strengthto the design; other designs may be used. The proximal coupling for thissubcutaneous lead is designed to prevent misuse in the vasculature,where the added stiffness caused by the coextruded central connectorcould be a perforation hazard. For at least these reasons, the lead 50shown in FIG. 3 may not be compatible with standard plug designs (DF-1,DF-4, etc.) in transvenous defibrillators.

The distal tip electrode 70 is shown with an opening, such as a suturehole, details of which are shown in FIGS. 4A-4B. FIG. 4A shows that thetip electrode 70 has an opening, such as a suture hole 72, coupled to abase portion 74. The tip electrode 70 is thinned in region 76 as shownin the side view of FIG. 4B. Other designs may be used.

For a three-incision implantation as shown in FIG. 2, above, the suturehole 72 would be used to anchor the distal tip of the lead 50 to thetough connective tissue membrane that covers the sternum/ribs (thefascia). Such suturing would be performed using access via the uppersternal incision 34 (FIG. 2). However, if the upper sternal incision 34(FIG. 2) is eliminated, anchoring by suturing to the fascia would not bepossible at the distal tip, so an alternative design is desired thatwould allow a physician the flexibility to perform a three incisiontechnique as shown in FIG. 2, or a two incision technique omitting theupper sternal incision 34 while using a distal anchor, with the samelead.

While the various examples herein are described in the contact of animplantable subcutaneous-only defibrillator, other devices/systems maymake use of these designs and concepts for anchoring a lead or otherdevice, for example, in an implantable monitor, an implantableneurostimulator, a transvenous pacemaker or defibrillator (orresynchronization system), a drug pump, or other devices.

FIG. 5 is an exploded view of a first anchoring device. The device 100has three pieces: a body 102 with arms 110, 112 and a nose 114, anattachment feature 104, and a plate 106 designed to couple with theattachment feature 104. In an example, the body 102 is made of arelatively flexible material such as a silicone rubber, while theattachment feature 104 and plate 106 are made a harder material such asa polyether-ether-ketone (PEEK). Other materials may be used.

The attachment feature 104 includes a post 116 to which the plate 106can attach with a corresponding hole 118. The post 116 extends in alateral direction relative to the length of the device 100, which lengthis understood to run from the nose 114 to the opposing end of theattachment feature 104.

The post 116 may include a notch, indent, annulus, protrusion, or otherelement to create a snap fit relative to the plate 106. In analternative embodiment, the plate 106 through-hole 118 may be threadedto allow a twist-on attachment. In yet another embodiment, the plate mayinclude a male connector, rather than hole 118, for insertion into thepost 116, which may be made hollow, or which could be replaced by anopening instead. Numerous other manners of connecting the plate 106 tothe post 116 can be envisioned. A separate pin may be provided to use tosecure the post 116 to the plate 108, for example.

In another example, all or parts of the attachment feature 104 and/orplate 106 may be conductive metal to facilitate cardiac or other signalsensing therethrough by an electrode to which the overall device 100 isattached. In yet another example, some or all of one or more of the body102, attachment feature 104, or plate 106 may be porous or have smallholes therethrough to allow sensing via tissue fluid passing therein tocontact the underlying electrode of the lead to which the device 100 isattached.

The body 102, attachment feature 104, and/or plate 106 may have acoating of a radiopaque material such as titanium or a radiopaquepaint/ink, or may integrate filaments, wires or the like havingradiopaque properties. In an example, the body 102 is insert molded ontothe attachment feature 104, using the alternating disks at 120 to ensurea secure connection. While not shown, the attachment feature 104 mayalso include screws, barbs, or hooks attached thereto to add to theconnection strength relative to the body 102. In addition, surfacetexturing or the like may be provided on the body 102, attachmentfeature 104 or plate 106 to encourage tissue ingrowth once implanted.

The attachment feature 104 includes a post 116 to which the plate 106can attach with a corresponding hole 118. The post 116 extends in alateral direction relative to the length of the device 100, which lengthis understood to run from the nose 114 to the opposing end of theattachment feature 104.

The post 116 may include a notch, annulus, protrusion, or other elementto create a snap fit relative to the plate 106. In an alternativeembodiment, the plate 106 through-hole 118 may be threaded to allow atwist-on attachment. In yet another embodiment, the plate may include amale connector for insertion into the post 116, which may be madehollow. Numerous other manners of connecting the plate 106 to the post116 can be envisioned. A separate pin may be provided to use to securethe post 116 to the plate 108, for example.

FIG. 6 is an assembled view of the first anchoring device 100 of FIG. 5.As noted, the body 102 can be insert molded onto the attachment feature104. Alternatively, the body 102 may be snap fit and/or secured by anadhesive to, welded to, or heat shrunk over the attachment feature. Inanother example, the body 102, with arms 110, 112, and the attachmentfeature 106 are a single piece. As shown in FIG. 6, the plate 106 isattached to the attachment feature 104. The overall assembly provides asmooth outer profile for introduction into a patient.

FIG. 7 shows the first anchoring device secured on the distal tip of alead. The device 100 is attached, using the attachment feature 104,mated to the plate 106, to the distal tip electrode 70 of an implantablelead similar to that shown above in FIGS. 3, 4A and 4B. In particular,the attachment feature 104 and plate 106 take advantage of an opening,such as the suture hole in the electrode 70.

FIG. 8 shows a second anchoring device relative to the distal tip of alead using a suture for attachment to the lead. The device is shownrelative to a lead 200 having an opening, such as a suture hole 202, ata distal tip 204 thereof. The distal tip 204 may or may not be anelectrode.

The anchoring device 210 includes arms or tines 212 in a generallyt-shaped configuration. The tines 210 meet at body 214, which extendsproximally from the tines 212 to define a bore having a closed end (atthe tines). As with other figures, the location where the tines 210 meetmay be described as a nose for the device 210.

Within the bore is an attachment feature that may take the form of asmall loop or eyelet, to which a suture 220 is tied. The suture 220 maybe permanently affixed to the body 214, rather than tied to a loop oreyelet. Rather than a suture 220, a metallic, polymeric or naturalmaterial (silk for example), or combination thereof, in the form of amonofilament, multifilament, braid, wound member, wire, staple, or clip,for example, or any suitable biocompatible filament having reasonablepull strength (for example, 1, 3, or 5 pounds, or more) may be used. Anyof the embodiments above or below may use these other materials and/orstructures instead of a suture. The suture 220 (or other attachmentstructure) is of a length that allows a gap between the anchoring device210 and the distal tip 204 of the lead 200.

The tines 212 and rest of the body 214 may be molded as a singlestructure. Alternatively, the tines 212 and rest of the body 214 mayovermolded onto a metal such as titanium to allow fluoroscopicobservation of position. The tines 212 may be flexible to allow them tocollapse during insertion in the patient for example as shown below inFIG. 10. The bore in the body 214 allows a distal portion of the lead200 to be within the bore/body 214 during insertion without beingpermanently fixed therein.

During insertion, the lead would be pushed through a hollow sheath withthe anchoring device 210 attached to the distal tip 204. As the lead 210pushed through the sheath, the distal tip 204 would rest inside the boredefined by body 214 to improve pushability. Once a desired implantlocation is reached and the sheath is removed, the lead 200 andanchoring device 210 would become slightly separated, with the suture220 securing the lead 200 to the anchoring device 210.

FIGS. 9A-9B show a third anchoring device. Referring to FIG. 9A, device300 includes a nose at 302 and arms at 304, 306 as above with the firstanchoring device. An attachment feature 310 includes a hook at 312. Theattachment feature is shown embedded in the body 308 of the device 300.

The hook 312 may be extendable/retractable, with a spring structure, ifdesired, or may simply be in a fixed location. In this particularexample, a dissolvable layer 320 is provided on the hook 312 for useduring introduction so that a lead to which the hook 312 is attached iskept at a distance from the rest of the anchoring device 300. FIG. 9Bshows an alternative in which a latch 330 is also provided to secure thedistal end of a lead (not shown) to the hook 312. The latch 330 may beflexible in a first direction, inward into the space defined by the hook312, to allow entry of the distal end of the lead (not shown) whilerelatively inflexible in the outward direction to prevent the lead fromescaping.

FIG. 10 shows insertion of a lead with an anchoring device thereonthrough a sheath. The sheath is shown at 400 and may be, for example, asplittable sheath having a frangible, scored, or perforated line ofweakness to allow it to be split along its length. The sheath 400defines a lumen 402 in which an anchoring device 410 is shown with thearms 412, 414 in a collapsed state, compressed against the inner sidesof the sheath 400. The anchoring device 410 is shown attached to a lead420 at the distal tip 422 thereof. The distal tip 422 may be similar tothose shown above, for example, in FIGS. 4A-4B. Once the anchoringdevice 410 exits the distal end of the sheath 402 and/or once the sheath402 is removed by splitting it, the arms 412, 414 will extend out to anon-retracted, relaxed state, to create an anchor for the lead 420 at adesired position.

FIGS. 11A-11B show a fourth anchoring device. Referring to FIG. 11A, theanchoring device 450 includes a body 452 having a nose 456 and arms 454,with an attachment feature at 458 extending from the proximal endthereof. In this example, the attachment feature 458 is a tab having ahole 460 therethrough as shown in the side view of FIG. 11B. The hole460 allows the anchoring device to be attached to the distal end of alead using a suture, a surgical stable, or other connector. If desired,the body 452 of this embodiment may also extend in the proximaldirection (where the nose 456 defines the distal end of the anchoringdevice 450) to define a bore for covering the distal end of the lead ina manner similar to that shown above in FIG. 8. The inclusion of such abore may make introduction through a sheath as shown in FIG. 10 easier.The attachment feature 458 may be secured to the body 452 by overmoldingor insert molding, adhesive, melt bonding, or welding, or the attachmentfeature 458 and body 452 may be formed as a single piece.

FIG. 12 shows a fifth anchoring device. In this instance, the anchoringdevice 470 includes a body 472 with arms 474 and a nose 476. Anattachment feature 480 includes a post 482 extending in a lateraldirection with an expanded head on the post, to allow placement throughan opening, such as a suture hole of a lead such that the head keeps thepost 482 secured to the lead. As before, the attachment feature 480 maybe secured to, or formed as a single piece with the body 472.

FIG. 13 shows a lead insertion tool having a sheath thereon. The leadinsertion tool 500 is sometimes also referred to as an electrodeinsertion tool or EIT. The tool 500 includes a handle at 502 and adistal tip at 504. The distal tip 504 may have a pointed but generallyblunt end, to facilitate dissection of subcutaneous tissue, but is notsharp so as to avoid piercing through the skin inadvertently. Otherdesigns may be used.

An opening, such as a suture hole may be provided on the tip 504, asshown. For example, the opening may be used to pull a lead duringintroduction from the lateral or axillary incision 30 (FIG. 2) to thexiphoid incision 32 (FIG. 2) by attaching a suture between the distalend of the electrode and the introducer tool.

It may be noted that the inclusion of a permanent anchor on the lead maynot be a simple expedient. For example, since a pulling step isperformed, such an anchor would need to have a design that allows thepulling step without harming the patient. Some concepts are shown inPublished US Patent Application No. 20120029335, the disclosure of whichis incorporated herein by reference.

Proximal of the distal tip 504 the lead insertion tool has a shaft 506on which a splittable sheath 510 is disposed. The splittable sheath isshown with a longitudinal line of weakness at 512, allowing it to splitin conventional fashion for splittable sheaths when the handles 514 aregrasped and pulled apart.

In use, and referring again to FIG. 2 as well as FIG. 13, the insertiontool 500 may be inserted via the xiphoid incision 32 and advanced to thelateral incision 30, tunneling therebetween. The distal tip 504 exitsthe lateral incision 30 and is secured to the distal end of a lead (suchas that shown in FIG. 3) with a suture. The tool is 500 is drawn out ofthe xiphoid incision, pulling the lead into the tunnel between thelateral incision 30 and the xiphoid incision. During each of these stepsthe splittable sheath 510 remains in place.

Next, the insertion tool 500 would be separated from the lead bysnipping the suture tying the two together. The insertion tool 500 isagain inserted through the xiphoid incision 32, this time going over theleft margin (approximately) of the sternum, or 1-2 centimeters to theleft thereof. Other directions and placements may be used, if desired.Once a desired position is achieved, the splittable sheath 510 is heldin position while the insertion tool 500 is removed, leaving thesplittable sheath in the now created second subcutaneous tunnel.

An anchoring device as in any of the above examples is then secured tothe distal tip of the lead. The lead with the anchoring device thereonis then advanced through the splittable sheath 510 until a desiredposition is attained. While holding the lead in position, the splittablesheath is then split and removed. A suture sleeve may be placed over thelead at the xiphoid incision 32 and/or at the lateral or axillaryincision 30. Finally, the proximal end of the lead would be inserted inthe implantable pulse generator for the system, and the procedure wouldconclude typically with acute testing, sensing configuration, and othersystem checks and configuration steps, and closure of all the incisions30, 32.

As relating more particularly to the lead introduction, FIG. 14 shows amethod in block form. The method 600 includes forming a tunnel 610,attaching an anchor 620, and inserting the lead with the attached anchor630.

In various examples, the step of forming a tunnel 610 may be performedwith a sheath such as a splittable sheath being used, as noted at 612.The step of attaching an anchor 620 may be performed using a snap fit622, a suture 624, a hook 626, or various other attachments discussedand shown above. The step of inserting the lead with the anchor 630 maybe performed by advancing the lead and anchor through a splittablesheath as noted at 632.

In an alternative example, the sheath may be omitted at block 610, andthe later step of inserting the lead and anchor 630 may be performedwithout the sheath in place, instead simply passing through the tunnel.

Each of these non-limiting examples can stand on its own, or can becombined in various permutations or combinations with one or more of theother examples.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In the event of inconsistent usages between this document and anydocuments so incorporated by reference, the usage in this documentcontrols.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” Moreover, in thefollowing claims, the terms “first,” “second,” and “third,” etc. areused merely as labels, and are not intended to impose numericalrequirements on their objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description.

The Abstract is provided to comply with 37 C.F.R. § 1.72(b), to allowthe reader to quickly ascertain the nature of the technical disclosure.It is submitted with the understanding that it will not be used tointerpret or limit the scope or meaning of the claims.

Also, in the above Detailed Description, various features may be groupedtogether to streamline the disclosure. This should not be interpreted asintending that an unclaimed disclosed feature is essential to any claim.Rather, inventive subject matter may lie in less than all features of aparticular disclosed embodiment. Thus, the following claims are herebyincorporated into the Detailed Description as examples or embodiments,with each claim standing on its own as a separate embodiment, and it iscontemplated that such embodiments can be combined with each other invarious combinations or permutations. The scope of the invention shouldbe determined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

What is claimed is:
 1. A kit for implantation of a subcutaneous leadcomprising: a subcutaneous lead having a plurality of electrodes thereonand a distal tip having an opening for use in attaching to anotherelement; an anchoring device comprising: one or more arms; a bodycoupling the one or more arms together and having a nose on one endthereof; and an attachment feature for attaching to the distal tip ofthe subcutaneous lead.
 2. The kit of claim 1 wherein the attachmentfeature of the anchoring device comprises a post extending in a lateraldirection relative to a direction from the attachment feature to thenose, wherein the post is configured to place in the opening in the tipof the subcutaneous lead.
 3. The kit of claim 2 further comprising asecuring piece for securing to the post, wherein the securing piece andthe post snap fit together.
 4. The kit of claim 3 wherein the securingpiece and attachment feature and body are configured to mate togetherwith the distal tip of the subcutaneous lead to form a smooth transitiontherebetween.
 5. The kit of claim 2 wherein the post includes anexpanded portion configured to pass through the opening in the tip ofthe subcutaneous lead in a snap-through fashion and remain secured tothe subcutaneous lead after passing through the opening.
 6. The kit ofclaim 1 further comprising an introducer tool having a sheath thereonfor creating a subcutaneous tunnel, the sheath sized to facilitatepassage of the subcutaneous lead and anchoring device therethrough, withthe anchoring device attached to the subcutaneous lead, after asubcutaneous tunnel has been formed using the introducer tool and afterremoval of the introducer tool from the sheath.
 7. The kit of claim 6wherein the arms of the anchoring device are flexible and configured tocollapse for introduction through the sheath.
 8. The kit of claim 1wherein the attachment feature of the anchoring device comprises a hookfor passing into the opening in the tip of the subcutaneous lead.
 9. Thekit of claim 8 wherein the attachment feature of the anchoring deviceincludes a latch adapted to allow the hook to pass into the opening inthe tip of the subcutaneous lead, but preventing escape therefrom. 10.The kit of claim 1 wherein the body of the anchoring device comprises abore having a closed end near the nose and an open end for receiving aportion of the distal tip of the subcutaneous lead, and the attachmentfeature is a suture secured to the body within the bore.
 11. The kit ofclaim 10 wherein the suture is long enough to allow the lead to beoutside the bore while remaining attached to the suture.
 12. The kit ofclaim 1 wherein the attachment feature of the anchoring device is a tabhaving an opening therethrough to allow an attachment member to be usedto secure the tab to the opening in distal tip of the subcutaneous lead.13. The kit of claim 1 wherein the arms, body and attachment feature ofthe anchoring device are formed of a single piece.
 14. The kit of claim1 wherein the anchoring device comprises a dissolvable portion that actsas a filler during implant of the anchoring device and subcutaneous leadinto a patient, the dissolvable portion adapted to dissolve afterimplantation to create a space between the body and the anchoredsubcutaneous lead after implantation.
 15. The kit of claim 1 wherein thearms of the anchoring device are flexible and configured to collapse forintroduction through an introducer sheath.
 16. The kit of claim 1wherein the arms of the anchoring device include a radiopaque coatingthereon.
 17. The kit of claim 1 wherein the anchoring device comprisesone or more radiopaque strands or filaments therein.
 18. The kit ofclaim 1 wherein the attachment feature of the anchoring device islocated on a proximal end of the body, and the nose is located on thedistal end of the body.
 19. A kit for implantation of a subcutaneouslead comprising: a subcutaneous lead having a plurality of electrodesthereon and a distal tip having an opening for use in attaching toanother element; an anchoring device comprising: one or more arms; abody coupling the one or more arms together and having a nose on one endthereof; and a means for attaching to the distal tip of the subcutaneouslead.
 20. The kit of claim 1 further comprising an introducer toolhaving a sheath thereon for creating a subcutaneous tunnel to implantthe subcutaneous lead, the sheath sized to facilitate passage of thesubcutaneous lead and anchoring device therethrough while the anchoringdevice is attached to the subcutaneous lead after a subcutaneous tunnelhas been formed using the introducer tool and after removal of theintroducer tool from the sheath.